The invention relates to a device for attaching and guiding one or several pulley cords of a Jacquard machine, comprising one or several pulley blocks, each pulley block being provided with at least two pulley wheels around which one or several pulley cords are passed and being provided with one or several pulley blocks guiding grooves for guiding one or several guiding elements which are designed to maintain the exact position of the one or several tackle blocks.
In order to bring the warp yarns and/or pile yarns of a weaving machine in their exact positions in order to realize, in combination with the weft yarns, the weave desired having the pattern desired, Jacquard machines are used. This is the case for flat weaving machines in which warp yarns are brought into their exact positions, in order to insert the weft to form, together with the weft yarns, the weave and figure desired. This is likewise the case for face-to-face weaving machines, in which pile yarns are brought into their exact positions in order to insert the weft, so that the pile warp yarns, together with the backing warp yarns and the weft yarns, should form the figure and weave desired. Similar Jacquard machines consist of at least two rows of hooks and of at least two blades each of which are permanently moving up and down in opposite phase with respect to a row of hooks and which may take along or not take along each of the hooks of that row. Taking along the hooks or not is controlled by selection elements, which, in the upper or lower position of the hooks of the Jacquard machine (dependent on their design), will retain the hooks for the duration of one or several cycles. Two hooks being directly opposed, which each are moved by a blade, the two said blades moving in opposite phase, constitute a complementary set of hooks. Hooks of one or two complementary sets of hooks, being selected or not, will take up different positions. By taking up these different positions these co-operating hooks will bring those warp yarns at the height desired to realize a fabric with a pattern, by a co-operation of these hooks with pulley wheels and inversing pulley wheels imposed by the interconnection, by means of the pulley cords passed round these pulley wheels and reversing pulley wheels, and because of these pulley cords being connected to one or several warp yarns (by means of a harness cord).
The Jacquard machines are built as compact as possible in order to be able to built in as many hooks as possible with additional selection elements and pulley block systems on a certain surface. The selection elements are made smaller and smaller and the pulley block systems have to follow this miniaturization. A pulley block device requires a regular maintenance and survey, for instance, to replace defective or worn out or broken pulley cords or pulley blocks. It is therefore necessary to find one's way among the other pulley systems and pulley cords in order to be able to replace the defective or worn out pulley block or cord. In doing so, there is a great risk that because of this manual operation a pulley block might be twisted through 180° with respect to the vertical axis (direction of the pulley cords) when replacing the defective or worn out pulley block or cord. Because of this, the twisted pulley blocks and crossed pulley cords will be the cause of a poor formation of the shed and of an untimely rupture of pulley cords and/or pulley blocks.
In order to avoid this twisting of the pulley blocks and the crossing of the pulley cords, a device is described in patent EP 0 839 937, in which partitions have been provided between the rows of hooks in order to protect the pulley blocks from getting twisted and the pulley cords from getting crossed. The partitions comprise a groove in which the pulley blocks are guided. Successive partitions with intermediate pulley block systems, hooks and selection elements are combined into one module.
The disadvantage of this device is, that the pulley blocks will become inaccessible because of the installation of the partitions and that the modules have to be taken away as a whole and have to be replaced at each problem or fault. Such modules are also expensive to be manufactured.
Another method to prevent the pulley blocks from twisting and the pulley cords from getting crossed consists in using tackles as represented in BE 9200461, where the pulley blocks have been provided with an elongated pulley block guiding groove, which is used to run a guiding spindle through these grooves of the various pulley blocks, the grooves of which are lying next to one another.
When replacing the pulley cords and pulley blocks, in this manner the risk is indeed eliminated that the adjacent pulley blocks will be twisted or the pulley cords will get crossed, but the disadvantage of this system is that the minimum length of the pulley block guiding groove in which the guiding spindle is moving when taking up different positions, has to be at least the length of the stroke of the pulley block so that the pulley block, in its different positions which it has to take up, will not collide with the non-moving guiding spindle. The guiding length lies between two successive pulley wheels and pulley cords and is the direct cause for an increase in installation height of the Jacquard machine.
In EP 0 839 937 a solution is suggested in which the pulley block guiding groove in the pulley block will serve as a guide for a second pulley block. Because of this the installation height of the device will be reduced and the installation will become more compact, particularly when using the pulley block guiding groove for the motion of the second pulley block, but the above-mentioned problem of the pulley blocks getting twisted and the pulley cords getting crossed will not be resolved by this method. If however, in this design, a pulley block guide to prevent the pulley blocks from getting twisted and the pulley cords from getting entangled, has to be realized, then the pulley block guiding groove has to be prolonged for the length of the stroke of the pulley block having a pulley block guiding groove, and a guiding spindle is installed through these grooves, because of which, in this manner, the same disadvantage occurs that the height of the Jacquard weaving machine is increased.
In many Jacquard applications, a pulley block guide in order to prevent the pulley blocks from getting twisted and the pulley cords from getting crossed, is important and necessary, but it will have the disadvantage that it will be the direct cause of a more expensive and a less maintenance friendly design or of an increase of the height of the Jacquard weaving machine. Considering the permanent tendency towards more closely woven fabrics, a higher Jacquard capacity is permanently required, whereas this higher Jacquard capacity on one and the same machine will cause the height of the Jacquard weaving machine to be increased continuously, which may cause problems with respect to the building height of a building in which such a Jacquard weaving machine has to be installed.